1. Field of the Invention
This invention relates to a sunscreen composition, and, more particularly, to a stable, uniform dispersion of ultrafine titanium dioxide or zinc oxide in an organic sunscreen agent with polyvinylpyrrolidone alkylated with an alpha-olefin as a dispersing aid.
2. Description of the Prior Art
Sunscreen compositions have been described extensively in the prior art. See, for example, U.S. Pat. Nos. 4,810,489; 4,820,508; 5,026,540; 5,041,281; 5,207,998; 5,219,559; 5,306,485; 5,445,815; 5,508,024; 5,599,529; and 5,603,863. Such compositions usually are formulated by admixing the several components in predetermined amounts. However, disadvantageously, such admixing often requires an elaborate sequence of addition of each of the components in expensive mixing equipment and order to assure a homogeneously dispersed composition.
Accordingly, it is an object of this invention to provide a sunscreen concentrate in the form of a stable, homogeneous dispersion from which a sunscreen composition can be formed readily by simple dilution with a carrier.
Another object of the invention is to provide a sunscreen concentrate comprising a stable, homogeneous dispersion of ultrafine titanium dioxide or zinc oxide, in an organic sunscreen agent, with polyvinylpyrrolidone alkylated with an alpha-olefin as a dispersing aid.
Still another object herein is to provide a waterproofing sunscreen concentrate having both an inorganic sunblock agent and a UV-absorbing organic sunscreen agent therein, in a hydrophilic or hydrophobic copolymer of polyvinylpyrrolidone and an alpha-olefin, wherein the particle size (u, microns) of the concentrate is about 0.01-0.2.mu., preferably about 0.05-0.1.mu., and a Brookfield viscosity of about 4,000 to 1,000,000 cps, preferably about 5,000 to 400,000 cps.
These and other objects and features of the invention will be made apparent from the following more detailed description of the invention.